The present invention relates to orthopedic casting methods, and more specifically relates to a method of applying an orthopedic cast by braiding fibrous casting yarns, in situ, around an injured body portion.
Traumatic injuries to body portions, particularly a fracture of a bone or damage to soft tissues, are frequently treated by immobilizing the injured body portion with a rigid cast. Heretofore, the application of medical casting materials required a labor intensive process of manually wrapping the injured limb with rolled strips of a tape-like plaster or fiberglass mesh fabric. The desired cast geometry for the type of body portion involved was achieved by wrapping, stretching, twisting, and layering, the rolls of plaster or fiberglass fabric over and around the injured body portion. In general, manual application of conventional casting fabrics is a lengthy and complicated procedure which requires a significant amount of skill and training, and many hospital personnel are required to dedicate a substantial portion of their medical training toward learning casting procedures. Although the conventional casting methods produce casts which have the rigidity and durability necessary for immobilizing injured body portion for extended periods of time, there are several disadvantages which are apparent. Because the rolls of casting fabric are manually applied in irregular, wrapped geometries, the amount of casting fabric utilized is much greater than is actually necessary and thus the casts are thick and heavy, and are burdensome and inconvenient to the wearer. Even further, the strips of casting fabric have exposed edges which often fray after hardening of the cast. The frayed edges cause portions of the cast to unravel, and therefore many casts must be replaced periodically. Another problem encountered because of the wrapping and layering procedure is that the several layers of the cast sometimes do not adequately adhere to one another. If the casting material is not applied quickly enough the impregnated matrix material can prematurely set and harden before the cast is completed, and thus, the layers of wrapped casting material do not correctly bond together. It can therefore be seen that the prior art casting methods are inadequate in these regards.